A conventionally-used technique extracts data by determining whether received data matches the extraction condition. For example, data including sensor data and point of sale system (POS) data is collected using stream data in which data is coded. Stream data includes coded data. Thus, the specific contents of the data are extracted by checking the stream data with master information.
For example, the master information includes a plurality of pieces of master data including a key and a plurality of columns. A method in which the extraction condition is determined after the master check or a method in which the master data is determined in advance and the determination result is checked with the stream data is known as the method in which the master data is extracted using the master information and the stream data.
For example, the method in which the extraction condition is determined after the master check specifies the appropriate master data from the master information using the code in the stream data as a key. Then, it is determined whether the data corresponding to each column in the specified master data satisfies the extraction condition. When the data satisfies the extraction condition, the master data is extracted.
The method in which determination process is performed in advance determines whether each column in the master information satisfies the extraction condition such that extraction information obtained by extracting the key of each column satisfying the condition is generated. Then, the extraction information of each column is referred to using the code in the stream data as a key. When the extraction information of each column includes the key, the master data is extracted.
PTL 1: Japanese Laid-open Patent Publication No. 04-102172
PTL 2: Japanese Laid-open Patent Publication No. 06-187379
PTL 3: Japanese Laid-open Patent Publication No. 2006-171800
The techniques, however, have a problem in that the process time to take to extract the data is increased as, for example, the number of columns, the number of records, or the reception frequency of stream data increases.
For example, when there are M pieces of master data in the method in which the extraction condition is determined after the master check, the determination process is performed M times per a piece of stream data. This elongates the process time. When there are N columns in the method in which determination is performed in advance, N pieces of extraction information are generated. Thus, the determination process is performed N times per a piece of stream data. This elongates the process time.